Forum user Matt Ownby has put together some code to be able to write data at full speed (50 MHz) to an SD card, and was kind enough to share it with us!  This is VHDL code for the Papillio One FPGA board that shows how to write to an SD card in a high-speed mode.

Here’s the lowdown on Matt’s work, per his description from the forums:

VHDL SD card writer v1.0 Features:

– Uses 4-bit SD mode, not 1-bit SPI mode (faster)
– Uses 50 MHz “high speed” mode, not 25 MHz “normal speed” mode (also faster)
– Logs to Papillio USB serial port (230400 bps) so you can see what is going on

Requirements:
– An SDHC card (older probably won’t work) that supports high-speed aka 50 MHz mode.

How to use:
– Get the pins of an SD card (or adapter) somehow connected to Papillio pins. Not discussed here as you are expected to have enough expertise to figure this out on your own

You can find the code (with readme) here.

Many thanks to Matt for sharing this with the community!  Go ahead and give it a whirl, and let us know what you think in the comments section as always!

(via the forums)